dangerous animal?
A “dangerous” animal is one that poses a threat to another animal,
human beings included. Animals are considered dangerous for
many reasons and not just because they bite or sting. The physical
characteristics of an animal, its temperament and the circumstances in
which it is encountered all affect how it will interact with people.

the
FACTS!

ONE OF THE MOST SERIOUS
THREATS comes from animals that
regard humans as prey to be eaten.
Fortunately, Australia does not have any
large terrestrial predators like tigers or
bears. The largest and most dangerous
Australian predators are Estuarine
Crocodiles and sharks, which do not
distinguish between humans and any other
sort of potential prey.

WILD ANIMALS DO NOT
ALWAYS REGARD HUMANS as
an immediate threat and some may
approach closely out of curiosity. In
other circumstances, people have
been injured or killed by wild animals
because they have encountered
an angry or scared animal that has
been already attacked by another
animal or person. People going to
the “rescue” of their pets are often
the victims of bites and stings that
were not really intended for them.

IN THE PAST 500 YEARS,
humans around the world have
caused the extinction of almost
1000 animal species.

Many people mistakenly believe that only
“ugly” animals, such as spiders and snakes,
are dangerous. This is not true. Some
dangerous animals ( eg. fish and cone shells )
are very attractive in appearance.

There are animals with venomous bites
or poisonous stings and some that use
chemicals to defend themselves. Others
have sharp teeth, claws and spurs that
can wound soft human skin. Then there
are animals that carry disease organisms
and parasites, which can affect our health
and well-being.

PEOPLE ARE A PROBLEM T00
Most deadly or dangerous animals
do not attack people unless they are
accidentally, or deliberately, provoked.
Even then, frightened animals often
perform a “threat display” to scare or
intimidate the “aggressor” before they
actually attack. Human beings often fail
to recognise these warnings, or ignore
them with disastrous results.
When threatened, the Frillneck Lizard
( Chlamydosaurus kingii ) raises its neck frill
to frighten would-be predators.

Text: Queensland Museum. Uncredited photography: Steve Parish

QUEENSLAND MUSEUM

TIGER SNAKE ANTIVENOM
was released in 1930 after several
years of research between the
Commonwealth Serum Laboratories
and the Walter and Eliza Hall
Institute in Melbourne. It was
the first antivenom developed in
Australia and, since then, another
12 antivenoms have been developed
for dangerous Australian snakes,
fish, spiders and ticks.

RON & VALERIE TAYLOR

MANY ANIMALS ARE ONLY
“DANGEROUS” at certain times
of the year, such as during the
breeding season (when there is
competition for mates), or during
a particular stage in their life cycle
(such as parasites). So little is
known about some Australian
animals that researchers are not
sure whether they are dangerous
or harmless.

Danger is not always related to size.
Protozoans are among the smallest
living organisms, but they are capable of
causing illness and death on a very large
scale. Similarly, “cute and cuddly” animals
are often considered harmless because of
their attractive appearance, but this isn’t
always the case.

It should always be remembered that “wild”
animals are exactly that — wild. They are not
tame pets or toys and should always be treated
with caution. A wild animal’s reaction to a
human being will always be unpredictable.

the
FACTS!

WHAT ARE THE RISKS?
Identifying “deadly and dangerous” animals is not always easy. Most people understand
the risks associated with large crocodiles or venomous spiders because these animals are
often found near humans and are known to cause serious injury and sometimes death.

A NEWLY DISCOVERED SPECIES
of taipan from Central Australia
(Oxyuranus temporalis) is known
only from a single specimen and
it has never been responsible for
biting a human. However, given its
close relationship to other taipans,
it must be regarded as a potentially
very dangerous species.

Other animals may possess dangerous attributes, such as highly toxic venom, but rarely
cause harm because they are not in frequent contact with humans. The Western Taipan
( Oxyuranus microlepidotus ) is one of the world’s deadliest snakes, but it inhabits the
remote Channel Country of far south-western Queensland and is seldom seen by people.
Normally placid or shy animals often become aggressive during the breeding season,
when males are more likely to fight over territories or females. Human sensitivity to animal
toxins is also an important factor and explains why bee or wasp stings can cause serious
allergic reactions in some people and not others.

HONEY BEES, DOGS, CATTLE
AND HORSES kill and injure more
people annually than native wildlife.

QUEENSLAND MUSEUM/BRUCE COWELL

THE AUSTRALIAN BUSH
can be a very dangerous place,
but its biggest danger is not
its wildlife. Vehicle breakdown,
remoteness, lack of water and
extreme temperatures are far more
hazardous for ill-prepared travellers.
In northern Australia, wet season
deluges can often strand travellers
for weeks on end.

Animals that are in poor health (like these brumbies) and that are living close together in harsh and
dirty conditions are very susceptible to the organisms that cause disease. Some animal diseases
can be transmitted to humans.

HUMAN FATALITIES IN AUSTRALIA 1980–1990
Crocodile attacks

Total deaths

Annual rate

8

0.7

Shark attacks

11

1

Bee stings

19

1.7

Lightning strikes

20

1.8

3455

345

32772

2979

Drowning
Motor vehicle accidents

CLARE THOMSON

Cause

APPROXIMATELY 120,000
DEATHS occur in Australia each
year. Animal- or wildlife-related
deaths do not appear among
the 10 most common causes
of death, which include motor
vehicle accidents, suicide, assault,
poisoning, drowning, burns, falls
and medical complications.

dangerous animals
Different sorts of animals pose different risks to humans.
Deadly and dangerous animals can be grouped according to the
type of harm they cause. Animals can be physically dangerous,
poisonous, venomous and carriers of disease and parasites.
THE WORDS “POISON”, “VENOM” AND “TOXIN ” are often used
interchangeably, but each has a different meaning.

the
FACTS!

ER
VA L
RON &

L
AY
IE T

OR

Poisons are substances that cause damage, illness or death if they are absorbed by
ingestion ( eating ) or contact ( touching ). Toxins are poisons produced by a plant or animal
for defence or predation. Most toxins interfere with the body’s biochemical processes
and cells. Venoms are toxins produced by animals that possess a mechanism to directly
transfer the venom to prey or aggressors via bites, stings, sprays and wounds.

THE PROCESS OF
TRANSFERRING VENOM
from one animal to another is
called “envenomation”.
THERE ARE ABOUT 3000 snake
bites reported Australia-wide each
year. Of these, 200–500 will require
treatment with antivenom and, on
average, only one or two deaths
will occur. In the early 1900s, death
rates were as high as 40–50% for
death adder and tiger snake bites
alone. The decline in the number
of deaths from snake bite is due
to the development of effective
antivenoms (below) and improved
medical treatment.
S anemones are considered venomous because they have special cells called nematocysts that
Sea
iinject
nje toxins into other animals. The risk for humans varies according to the species of anemone.

TOXIN ALERT!
Poisonous animals produce their own
toxins or extract toxins from other
sources (such as the food they eat).
The toxins may be stored in an animal’s
skin, its body tissues or internal organs
and can become more concentrated
as the animal grows or ages. When a
poisonous animal is attacked, the toxin
is passed by ingestion or through skin
contact. Frogs and toads often have
poisonous skin secretions and some
insects are able to store toxins in their
bodies from the plants they eat.
The Cane Toad ( Bufo marinus )
is an introduced pest that is
toxic at all stages of its life.

Text: Queensland Museum. Uncredited photography: Steve Parish

If you do not recognise an animal,
do not touch it. Some dangerous
animals may resemble harmless
species, but can only be identified
by experts or scientific examination.

VENOMOUS ANIMALS
Venomous animals also produce
their own toxins, but they are able to
inject these toxins into other animals via
stings, spines, sprays and fangs. Some
animals, such as snakes and cone
shells, have evolved venoms that not
only disable their prey, but also start
to break down the victim’s body so that
digestion is easier.

In Australia’s early days camels were invaluable to
explorers and settlers, but they are known to be
cantankerous animals and quick to bite.

Any animal that is as big as or larger than
a person can be dangerous, especially if it
regards a human as an easy meal.
Few Australian native animals are large
enough to pose this sort of threat, but
livestock, such as cattle and horses, have
the size and weight to crush, trample and
kill. Adult wild pigs can also be dangerous.
Many animals have sharp claws and teeth,
horns and tusks, piercing spines and
blade-like projections, or hard beaks on
their bodies. These animals can inflict
deep wounds, punctures and severe
lacerations in self-defence.

QUEENSLAND MUSEUM/JEFF WRIGHT

DISEASE-CARRYING
ANIMALS

Mosquitoes are often considered to be the most
dangerous animals on the planet because of the
number of diseases they transmit to humans.

Compared to a human, a mosquito is a
small, fragile creature, but some species
are regarded as the deadliest animals
on Earth. Mosquitoes carry parasites,
bacteria and viruses that can cause
life-threatening diseases such as Malaria,
Japanese Encephalitis and Dengue Fever.
Other types of insects are also known
to transmit disease. Many other kinds of
animals carry diseases and parasites that
can affect humans. People can be directly
infected through bites and scratches,
or indirectly through excretions. Some
particularly nasty diseases originate
with our closest animal companions —
domestic pets and livestock.

QUEENSLAND MUSEUM/JEFF WRIGHT

the
FACTS!
TOXINS OFTEN TARGET A
PARTICULAR PART of the victim.
Neurotoxins affect the nervous
system; cytotoxins attack the body
cells; myotoxins damage muscles;
and haemotoxins destroy blood
cells and stop blood clotting.
THE COMPOSITION OF A
VENOM is determined by the prey
an animal eats. Venoms, such as
those produced by snakes, are
complex and contain many kinds of
toxic substances.
BOTULISM IS A SEVERE TYPE
OF FOOD poisoning caused by a
microscopic bacteria (Clostridium
botulinum). The bacteria lives on
decaying matter and the toxin is
one of the most poisonous natural
substances in the world. Food that
is not cooked, preserved or canned
properly provides ideal conditions
for the bacteria to grow. Botulism
affects the nervous system and can
also be fatal. Fortunately, outbreaks
in the human population are rare.
ANIMAL POISONS AND VENOMS
are now being used to develop
new medicines. Venoms and
poisons contain many different
substances and scientists are
finding that some of these may
be useful for treating illnesses.
For example, the venom of some
scorpions contains substances
that could help diabetes sufferers.

Sharks
— supreme predators
Sharks are considered the most terrifying of all marine
creatures and shark attacks often appear brutal
and violent. One species, the White Shark
( Carcharodon carcharias ), is feared above all
others. The reality is that although some 40 shark
species have been known to attack humans, only three
species are to blame for most injuries and fatalities.

the
FACTS!

ANY ANIMAL IS AT A DISADVANTAGE when it is out of its element and humans are
no exception. Whether wading in the shallows, or swimming in deep water, humans are
no match for powerful aquatic predators like sharks.

THE SHAPE of a shark’s teeth
is influenced by its diet, ranging
from needle-like teeth for gripping
fish and flat teeth for crushing
molluscs to triangular, serrated
teeth for shearing flesh from marine
mammals and large fish.

THE WHITE SHARK (below) is
the only “warm-blooded” shark.
All other sharks are cold-blooded.
White Sharks are able to keep their
body temperature higher than that
of the surrounding water.

RON & VALERIE TAYLOR

WHITE SHARKS have acute
eyesight, hearing and sense
of smell. They can also detect
low-frequency vibrations and
minute electric fields and they
respond to taste and touch.

The maximum size reached by White Sharks has been the source of many debates and wild
speculation. Research indicates that the maximum total length is likely to be about 7 m.

BULL SHARKS are able to move
between saltwater and freshwater
and have been found thousands of
kilometres from the sea in the
upper reaches of the Amazon River.
Bull Sharks also inhabit Australian
rivers and have been recorded up
to 90 km inland from the mouth of
the Brisbane River in Queensland.

RON & VALERIE TAYLOR

RON & VALERIE TAYLOR

TOP OF THE FOOD CHAIN

Sharks, like this whaler shark
( Carcharhinus sp. ), are sleek, active
predators that are constantly on the move.
In contrast, bottom-dwelling sharks have
a body shape that is appropriate for a
more stealthy life on the sea floor.

Text: Queensland Museum. Uncredited photography: Steve Parish

Sharks are an evolutionary success
story. They have been around for
about 400 million years and “modern”
sharks have existed almost unchanged
for some 250 million years. The living
species range from the harmless
15 m Whale Shark ( Rhincodon typus )
to the 15 cm Dwarf Lantern Shark
( Etmopterus perryi ).
Sharks eat almost anything, from
plankton and other invertebrate animals
to large fish, marine mammals and, if
the opportunity arises, humans.

Do not swim alone and avoid the water at night, dawn and
dusk. Do not enter the water if sharks are present. Heed
shark alarms, but do not panic. If attacked by a shark, try
to hit the animal as hard as possible on the snout.
The eyes and gills are also sensitive.

SHARK ATTACK
Despite their reputation, sharks are not a serious threat to human life.
Worldwide, only about 100 attacks are recorded each year and in Australia
the incidence of fatal shark attack is low — less than one fatality per year.

the
FACTS!

A human handling a shark is the main cause of attack. This occurs when
people attempt to remove sharks from fishing nets or when they try to grab
sharks or feed them. Most attacks occur in inshore waters when sharks are hunting.
Attacks are also common near steep ocean drop-offs where prey congregates.

Divers can be protected from the bites of
small sharks by wearing coats of metal
links or “chainmail”.

SHARKS AND THEIR CLOSE
RELATIVES, the rays, are
“cartilaginous fish”, which means
that their skeletons are composed of
light-weight, flexible cartilage.

RON & VALERIE TAYLOR

Sharks in a “feeding frenzy” should
never be approached. They become
excited when attacking schools of fish,
when water oxygen levels are elevated
or when there is blood in the water. It
is possible that some shark attacks are
opportunistic and may result from the
shark mistaking swimmers and surfers
for large prey animals.

MOST SHARK SPECIES are
harmless and many are now under
threat worldwide from fishing and
habitat loss. More than 160 species
of shark have been recorded in
Australian waters.

SHARKS AND RAYS have tough
skin studded with numerous,
tooth-like scales known as “dermal
denticles”. The shape of the
denticles varies among species and
is a useful identification tool.

THE BIG THREE
The White Shark, also known as the Great White or White Pointer, is thought to be
responsible for nearly half of all the unprovoked fatal shark attacks on humans worldwide.
It occurs in temperate to tropical waters around the world and research shows that White
Sharks are very mobile, some even travelling across oceans.

The Bull Shark ( Carcharhinus leucas ) has an aggressive and unpredictable nature and
is often found in rivers and canals. It is believed to be responsible for around 13% of
unprovoked attacks worldwide and feeds on fish (including other sharks), dolphins, turtles,
birds and other marine animals.
Below: The Tiger Shark has a reputation as an animal that will eat almost anything
— it is a both a predator and a scavenger.

RON & VALERIE TAYLOR

The Tiger Shark ( Galeocerdo cuvier ) is named for the dark spots, blotches or bands
across its back. It is smaller and slower than a White Shark and is found in temperate and
tropical waters where it causes about 15% of unprovoked attacks.

RON & VALERIE TAYLOR

SHARK AND RAY SKIN can be
made into leather ( shagreen ). The
rough texture of shagreen makes it
an ideal covering for sword grips.
SHARK TEETH are embedded
in the flesh of their jaws and the
outermost rows are constantly shed
and replaced by “waves” of new
teeth that form inside the jaws.

Crocodiles
— ancient reptiles
Crocodiles are truly awesome animals. These low-slung,
armoured reptiles have been the “top” predators in
wetland and marine environments for millions of
years. The “man-eaters” among them have
long inspired terror among humans.

the
FACTS!

LIKE SHARKS, crocodiles have a long
evolutionary history. They have remained
relatively unchanged over the past
80 million years. Their ancestors were
land-dwelling predators that existed before
the dinosaurs.

CROCODILES EVOLVED from
land-dwelling reptiles. Fossils
of Junggarsuchus sloani, a
slender, 1 m crocodilian from
China, show that their ancestors
had powerful jaws long before
crocodiles returned to the water.
The Junggarsuchus fossils are
230–150 million years old.

Tropical northern Australia is home to two
species of crocodile — the Freshwater
Crocodile ( Crocodylus johnstoni ) and
the much larger Estuarine (or Saltwater)
Crocodile ( Crocodylus porosus ).

IAN MORRIS

ABORIGINAL AND TORRES
STRAIT ISLANDER peoples have a
special relationship with crocodiles.
Some groups regard crocodiles
as religious icons or totems and
others believe they are the spirits
of creation ancestors. Crocodiles
are also a food source for some
Indigenous peoples, who take eggs
from nests and hunt adults.

THE SEX OF ESTUARINE
CROCODILES is determined by the
incubation temperature in the nest.
If the temperature is below 30 ºC,
females will hatch. Males will appear
above 32 ºC.

IMPRESSIVE HUNTERS
Estuarine Crocodiles are the largest
living crocodile. They range from
India to Vanuatu and the Solomon
Islands. In tropical northern Australia,
these crocodiles inhabit estuaries,
rivers, swamps, beaches and offshore
islands. They are sometimes seen
basking on the banks of watercourses,
or swimming or floating just below the
water’s surface. Crocodiles are skilful,
stealthy predators. Most attacks occur
at, or near, the water’s edge. The muscular tail is used to power an attack, driving
the animal forward or enabling it to lunge vertically with explosive force.
IAN MORRIS

Crocodiles have excellent underwater and
night vision combined with a keen sense of
smell. Small sensory buds around the top
and bottom jaws allow crocodiles to detect
vibrations — crucial when hunting in murky
water. Their jaws have immense crushing
power, enabling them to easily break skulls
and other bones. Prey is swallowed as
large chunks. If prey is too big to swallow
whole, the crocodile may roll several times
or shake its head in an attempt to break off
a more manageable piece.

A large male Estuarine Crocodile is capable of taking an animal as large as a Water Buffalo
( Bubalus bubalis ), but most of its diet consists of crustaceans, fish, turtles, lizards, small
mammals and birds.
Text: Queensland Museum. Uncredited photography: Steve Parish

Physically
dangerous

Precautions
Never assume that crocodiles are not
present just because they cannot be seen.
Observe warning signs and be very careful
around tropical creeks, rivers and lagoons.

THEY MAY BE SMALLER BUT...
The Freshwater Crocodile inhabits inland waterways and the tidal reaches of
some rivers across northern Australia. It is smaller than the Estuarine Crocodile
and has a long narrow snout, fine needle-like teeth and a row of four large
scales on the neck immediately behind the head.
Freshwater Crocodiles are not normally regarded as dangerous but they can
cause serious injuries if they do bite. These crocodiles are active during the
day, although they mainly hunt at night. They ambush prey at the edges of
rivers, creeks and lagoons, or in shallow water, catching insects, crustaceans,
fish, frogs, lizards, turtles, bats and birds and sometimes small mammals.

OR
IAN M

RIS

the
FACTS!
FATAL ATTACKS by Estuarine
Crocodiles are a rare occurrence
in Australia. Victims of non-fatal
attacks can be injured, not only by
the bite, but also by blows from
the tail. In high risk areas, always
observe crocodile warning signs
(below). On average, there is one
fatal attack every two years.

Male Freshwater Crocodiles weigh up to 60 kg and grow more than 2.5 m long. Females weigh up
to 30 kg and reach 1.8 m.

STAYING SAFE
• Stay alert around waterways and
lagoons and away from the water’s edge.
• Don’t return to the same place at the
water’s edge on a regular basis.

RON & VALERIE TAYLOR

• Don’t assume it’s safe to swim just
because there are no warning signs.

CLARE THOMSON

• Don’t clean fish near the water or discard
fish scraps in the water.
• If you see a crocodile slide mark ( a
crocodile moving into the water from
a river bank will leave a characteristic
mark ), stay well clear of that area.
• Avoid places where native animals or
cattle drink.
• Be particularly careful at night.
Right, top to bottom: Freshwater Crocodile; Estuarine Crocodile. Both species have attacked humans,
though the Freshwater Crocodile is generally not considered dangerous.

STUDIES HAVE SHOWN that
crocodiles are able to convert as
much as 50–70% of their food
into growth and energy ( humans
use only 3–4% ). This means that
crocodiles can go for months
without eating.

TO MARINE ANIMALS, PLASTIC
BAGS looks like sea jellies. Plastic
bags will remain in the gut of sea
creatures and can be fatal. Marine
animals also confuse rubber,
balloons and confectionery wrappers
with food. Avoid littering beaches
and dumping rubbish from boats.

Some animals are not only immune
to stinging sea jellies, they are
able to eat them and absorb the
poisonous compounds to use for their
own defence. For example, some
nudibranchs (sea slugs) that prey on
sea jellies can even recycle the stinging
nematocysts. The bright blue or violet
“sea lizards” (Glaucus spp.), do this so
effectively that they sting by touch.

“TRUE” SEA JELLIES
IRUKANDJI SYNDROME is a
severe medical condition caused by
box jelly stings. The sting may not
be immediately painful. After a while
the victim experiences severe pain
in their head, back, chest, abdomen
and muscles. Other symptoms follow,
including nausea and restlessness. In
susceptible individuals, complications
can prove fatal.
SCIENTISTS originally believed
that a small carybdeid box jelly,
Carukia barnesi, was responsible
for the condition. Its bell is only
1–2 cm across, but its four tentacles
can trail up to 1 m. The animals are
found mostly in deep reef waters,
but wind sometimes sweeps them
inshore. It is now thought that
several different species of sea jelly
cause Irukandji Syndrome.

The “true” sea jellies are the animals that
are most familiar to beach-goers. They
include the Lion’s Mane (or Hair) Sea Jelly
( Cyanea capillata ), sea nettles ( Chrysaora
spp. ), upside-down sea jellies ( Cassiopeia
spp. ), “blubbers” ( Catostylus mosaicus )
and the Moon Jelly ( Aurelia aurita ).
The jellies drift at the mercy of the currents,
often accumulating in sheltered bays and
estuaries. They “swim” using a pumping
motion, which does little more than move
them up or down in the water. In Australia
“true” sea jellies can deliver unpleasant
or severe stings ( causing cramps,
coughing, blistering and long-lasting pain );
fortunately, however, there have not been
any recorded fatalities.

Text: Queensland Museum. Uncredited photography: Steve Parish

RON & VALERIE TAYLOR

SEA JELLIES ARE EATEN by a
number of large marine animals,
including Leatherback Turtles
( Dermochelys coriacea ) and Ocean
Sunfish ( Mola mola ).

SEA JELLIES RANGE from
delicate gossamer bells that trail long,
wispy tentacles to large blubbery masses
with thick clusters of stubby, finger-like
tentacles. Some have transparent bodies,
while others are highly coloured and
ornate, with a “frill” between the upper bell
and the lower tentacles. There are three
groups — “true” sea jellies, “box” jellies (or
sea wasps) and hydromedusae.

Timoides agassizii is an example of a
hydromedusa. These jellies are smaller and
more delicate than “true” sea jellies or box
jellies. They are the sexual reproductive stage
of hydrozoans.

RON & VALERIE TAYLOR

the
FACTS!

Sea jellies ( “jellyfish” ) are free-swimming or floating cnidarians.
They are mainly encountered in marine waters, but a few species
live in freshwater. Fortunately, most jellies are harmless, but some
can deliver painful and even fatal stings.

Sea jellies can be delicate and ethereal
creatures. Many are transparent and barely
visible as they drift in the water.

the
FACTS!

NASTY JELLIES
Sea wasps or “box” jellies can be distinguished from sea jellies by their square, or
cube-shaped, bell. Only 30 species are known, but they include some of the most
dangerous of all marine animals.

EACH TENTACLE of a Box Jelly
is armed with an estimated 5000
nematocysts.

QUEENSLAND MUSEUM/JEFF WRIGHT

True sea jellies are blind “drifters” that must wait for hapless prey to blunder into
their tentacles. In contrast, box jellies have primitive “eyes” on each side of the
bell so they can hunt and avoid objects in the water. They are also capable of
swimming at a speed of about 3 knots ( approximately 5.5 km/h ).

CARYBDEA RASTONI is the only
box jelly regularly recorded from the
cooler waters of southern Australia.
Its sting is only noticeable on
sensitive areas like the lips.

The two main families of box
jelly are the Chirodropidae and
Carybdeidae. Chirodropidae
have multiple tentacles hanging
from each corner of their bell.
Carybdeidae have a single tentacle
hanging from each corner.

The box jellies of the genus Tamoya are
mainly found in tropical waters. Tamoya
virulenta is one species that can be
encountered in southern Queensland
waters. Like all carybdeids, it has four
tentacles that are capable of delivering
a very painful sting.

The Box Jelly ( Chironex fleckeri ) is probably the world’s deadliest marine animal. It
is common in northern Australian waters in the warmer months of the year. The jelly
measures up to 20 cm along each side of its bell and has as many as fifteen tentacles,
which trail 3 m behind or below the bell.
Box Jellies seem to move
inshore in calm waters on the
rising tide and gather near the
mouths of rivers, estuaries
and creeks following rain.
Beaches are often closed
during “stinger season” and
protective nets have been
installed at many popular
tourist destinations in northern
Australia. Some people wear
specially designed, cover-all
swimming costumes for
further protection.

SEA JELLIES range in size from
12 mm to the Giant Lion’s Mane Sea
Jelly ( Cyanea arctica ) of Northern
Hemisphere waters. This jelly has
tentacles more than 40 m long and
measures more than 2 m across the
bell!
THE BOX JELLY swims with a
jet-like pumping motion. The season
for the Box Jelly starts with the
onset of the wet season across the
top of northern Australia and lasts
until autumn.

RON & VALERIE TAYLOR

Right: More than 60 people are
known to have died after being
stung by a Box Jelly, sometimes
within minutes of the attack.

RON & VALERIE TAYLOR

DEADLY JELLY

THE UPSIDE-DOWN sea jellies
rest upside-down on their bell,
tentacles pointing up on seagrass
meadows or sandy and muddy
bottoms near mangroves.

Precautions
Never swim alone, or outside protected
areas. Douse the victim with vinegar to
deactivate the nematocysts. Apply first aid
and seek medical attention immediately.

Venomous

Spiders
& other arachnids
Thousands of people are bitten by spiders every year in Australia, but
only a relatively few bites cause problems. There have been very few
deaths from funnel-webs, or the notorious Redback Spider, since the
development of antivenoms. Other arachnids that pose a threat to
humans include scorpions, ticks, millipedes and centipedes.

The Redback Spider ( Latrodectus hasselti )
is probably Australia’s most famous
spider. It is found throughout Australia and
is common in disturbed, industrial and
residential areas.
QUEENSLAND MUSEUM/JEFF WRIGHT

Female Redback Spiders are black to
brown, usually with a bright orange to
red stripe on the upper abdomen and an
“hourglass” shaped red or orange mark
underneath. Juveniles also have white
markings on the abdomen.
The Brown Widow Spider ( Latrodectus
geometricus ) is a closely related species
introduced to north-eastern Australia.
This species lacks a red stripe and
has a yellow hour-glass pattern on its
lower abdomen. It is not as dangerous
as the Redback Spider.

THE BROWN WIDOW is the
most active breeder among widow
species, producing up to 5000
young per female per season. It
appears not to be as adversely
affected by winter and has the
potential to become a considerable
pest in Australia.

QUEENSLAND MUSEUM

TIMID SPIDERS

QUEENSLAND MUSEUM

WOLF SPIDERS ( Lycosa spp. ) are
common ground-dwelling spiders
(below). Usually drab-coloured, with
dark brown or black heads, some
wolf spiders have lighter markings
or an “X” shape on their heads.
Wolf spiders are often disturbed in
gardens where they burrow in the
soil or live among fallen leaves
and shrubs. Most bites produce
only mild effects, but they can
also cause itchiness, red welts,
bruising, nausea, localised pain
and prolonged headaches
among other symptoms.

Right: The Redback Spider is the Australian
representative of the notorious widow group
of spiders found elsewhere in the world.

Black House Spiders (Badumna insignis)
construct distinctive webs in crevices in
tree trunks, among rocks and around
homes and buildings. The webs are very
lacy with one or more entrances. Black
House Spiders are black or very dark
grey with an indistinct pale pattern on
the abdomen and legs. Their bite may
cause severe pain and other unpleasant
symptoms. Fortunately, these spiders
are timid and retreat deep into their web
if disturbed, so bites are rare and usually
happen when people are removing the
unsightly webs.
Left, top to bottom: Black House Spiders will
build their webs along window/door frames.

Text: Queensland Museum. Uncredited photography: Steve Parish

Mottled scorpions belong to at least three genera that are
all very difficult to identify.

Scorpions are distinctive
arachnids with a long,
sting-bearing tail and
a pair of pincers at the
front of the body. They
are found throughout
Australia and some, such
as the brown scorpions
( Liocheles spp. ) are
common in gardens.
Scorpions shelter under
logs/rocks and in shallow
burrows in earth banks.

There are also desert species that construct deep spiral burrows in sand.
Scorpions are mostly nocturnal, but are sometimes active during the day. Some
Australian species have a painful sting, but none are considered dangerous.
If ultra-violet light ( “black light” ) is shone on live or fossil scorpions, they glow or
“fluoresce”. The fluorescence is caused by an unidentified substance in a very thin
outer layer ( cuticle) of the scorpion’s “body armour” ( exoskeleton ).

the
FACTS!
MOST TICKS are external,
bloodsucking parasites of
mammals, birds and reptiles.
They favour forest, tall grass and
shrubby vegetation, where they
climb onto plants and wait to
jump on a passing host. Ticks
can transmit diseases to humans
and some are also venomous.
The Australian Paralysis, or
“Scrub”, Tick of eastern Australia
produces a paralysing toxin in its
salivary glands that can be fatal to
small animals and babies. In adults,
bites can cause intense itching and
sometimes more serious reactions
that require hospitalisation.
CENTIPEDES always have an odd
number of pairs of legs. The known
range is 15–191 pairs.

LONG, LEGGY
ARTHROPODS
Centipedes and millipedes are arthropods
( class: Myriapoda, meaning “many pairs
of legs” ). Centipedes are carnivores and
are armed with a pair of fangs containing a
poison gland. Bites from large centipedes
(such as Ethmostigmus spp.) may cause
severe pain, swelling and associated
complications. The large structures at the
rear of a centipede are not stings; they are
sensory organs called cerci.

Right: The Giant Centipede ( Ethmostigmus
rubripes ) is the largest of all Australasian
centipedes. The maximum head and body
length is around 13.5 cm. Giant Centipedes are
powerful predators that can capture and kill small
vertebrates, like this small snake. They will also
scavenge freshly killed animals on roadways.

IAN MORRIS

Millipedes feed on plants and decaying
vegetable matter, so they have no need for
fangs. When threatened, they can release
toxins that stain and irritate skin.

Snakes
— deadly reptiles
Venomous snakes are probably the most feared animals in the
Australian bush. They can be encountered anywhere on the
mainland, throughout Tasmania and on many offshore islands.
Some can even be found in coastal marine waters.

HOLLOW-FANGED FAMILY
QU

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the
FACTS!

The largest family of Australian snakes is the Elapidae. This family also includes the
deadly cobras of Africa and Asia. Elapid snakes have large hollow fangs at the front of
their upper jaws. A duct under the skin connects each fang to a venom gland located
at the rear of the head. When the snake bites down, muscles squeeze the glands and a
stream of venom flows along the duct into the fang.

IT IS COMMONLY BELIEVED
that all snakes are venomous. Many
have toxic saliva, but only around
300 of the 2700 known species
actually have sophisticated venomdelivery systems.

Young snakes may have bright or distinctive patterns unlike the adults. The distinctive head pattern
of this young Eastern Brown Snake ( Pseudonaja textilis ) will be lost as it ages.

VENOMOUS SNAKES have the
ability to control venom release and
many can deliver what is known as
a “dry bite”.

GIVEN A BAD NAME

STUDIES OF EASTERN BROWN
SNAKES have shown that smaller
individuals are more likely to flee
than larger snakes and that most
(77% ) give some form of warning
display before striking. Researchers
also found that 25% of all strikes
were a bluff.

Text: Queensland Museum. Uncredited photography: Steve Parish

STEVE SWANSON

RESEARCH SUGGESTS that
venoms evolved as snakes started
to become smaller and more
“advanced” around 60 million years
ago. The earliest snakes were large,
heavy-bodied animals like modern
pythons and boas.

Death adders ( Acanthophis spp. ) are
short squat snakes about 50–70 cm
long. They have broad heads, small
eyes and a tail that ends in a short
spine. At least four species occur in
Australia, living in all habitats except
rainforests. Unlike other elapids, death
adders are not active predators,
preferring to lie curled and concealed
with their tail exposed. The tail is
wriggled to lure prey into striking range.
Dangerously venomous.
The Common Death Adder ( Acanthophis
antarcticus ) varies in colour.

Do not provoke, handle or attack snakes.
If bitten, seek urgent medical attention.

the
FACTS!

COPPERHEADS
Despite their common name, none of
the copperheads ( Austrelaps spp. ) have
a strongly copper-coloured head. These
snakes are often found in alpine areas
and habitats considered too cold for
other snakes. They feed on frogs and
skinks, but will also prey on birds and
small mammals. When cornered, they will
hiss loudly and thrash from side to side.
Dangerously venomous.

SMALL-EYED SNAKE

THERE ARE THREE groups
of Australian elapids â&#x20AC;&#x201D; the
land-dwellers ( 91 species ), the sea
snakes ( 31 species ) and sea kraits
( two species ). The members of all
three groups are so closely related
that the differences between them
are due to their particular lifestyles.

QUEENSLAND MUSEUM/JEFF WRIGHT

BLACK WHIPSNAKES
Whipsnakes (Demansia spp.) are swift
daytime predators of lizards. They have
keen eyesight and will pursue prey. The
small whipsnakes are not regarded as
dangerous, even though bites may cause
unpleasant local symptoms. The Greater
Black Whipsnake (Demansia papuensis)
and the Lesser Black Whipsnake (Demansia
vestigiata) of northern and eastern Australia,
should be regarded as potentially dangerous
due to their size (more than 1 m).
Left: Black Whipsnake (Demansia vestigiata)

QUEENSLAND MUSEUM/JEFF WRIGHT

MOST WHIPSNAKE SPECIES
are fast-moving, slender snakes
with distinctive facial and/or head
markings (below).

QUEENSLAND MUSEUM/JEFF WRIGHT

The Small-eyed Snake is responsible
for one fatality and numerous serious
bites.

MOST DEATH ADDERS prefer dry
open forests, woodlands, grassland,
rocky ranges and deserts, although
the Common Death Adder also
occurs in shrub and heath.

QUEENSLAND MUSEUM/BRUCE COWELL

The Eastern Small-eyed Snake
(Cryptophis nigrescens) of coastal
eastern Australia looks like a
small Red-bellied Black Snake
(Pseudechis porphyriacus) because
it is black or dark grey above with a
reddish or pinkish belly. It occurs in
or near forested areas, often close
to habitation. It is active at night and
preys on snakes, lizards and frogs.
Dangerously venomous.

STEVE SWANSON

Left: The Highlands Copperhead ( Austrelaps
ramsayi ) is the most widespread of the
copperheads. It occurs as far north as the
New England Tableland of New South Wales.

Human beings can contract diseases from other people or
from other animals. Disease-causing agents are known as
“pathogens” and together they can attack almost any part of the
body, from the surface of the skin to internal organs.

LA N

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DM

PATHOGENS INCLUDE VIRUSES, bacteria, protozoa, parasites and fungi.
Some diseases affect only people. Pathogens that cause disease in both animals
and humans are known as “zoonoses”. Fortunately, zoonotic disease is not common
and can often be prevented if precautions are taken.

SE
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FACTS!

VIRUSES
Viruses are unlike any other organism and
for many years scientists debated if they
were actually “living things”. Viruses can
only replicate by infecting a host cell. They
cannot reproduce on their own. Viruses
can infect plants, animals, fungi and even
other micro-organisms. They are extremely
tiny and can only be viewed individually
using powerful electron microscopes.

FUNGI ARE SINGLE- OR
MULTI-CELLED ORGANISMS that
include yeasts, moulds ( below ) and
mildews. Many fungus species grow
as a web-like structure ( mycelium )
made up of many strands ( hyphae ).
The mycelium is sometimes visible
but it often grows in soil or inside
organic matter, plants or animals.
Mushrooms and puffballs are fungi
but they are the reproductive “fruiting
bodies” of particular species.

B.S.I.P./AUSCAPE

C

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Right: Viruses cause a wide variety of human
ailments. Dengue ( DF ) and dengue hemorrhagic
fever ( DHF ) are caused by a group of four
closely related viruses.

PROTOZOA & SIMILAR ORGANISMS

QUEENSLAND MUSEUM

Protozoa are also single-celled organisms. They are sometimes regarded as either
animals (in that they move and obtain food from their environment) or plants (if they
have structures that contain chlorophyll). Protozoa are important parasites and
pathogens and can cause serious diseases like malaria.

THE LARGEST KNOWN SINGLE
ORGANISM on Earth is a fungus. An
individual Armillaria ostoyae ( a “honey
mushroom” ) growing in western
Washington State in the United
States covers nearly 9 km ² and
weighs perhaps 3600 tons. It may be
about 2400 years old. An individual
Armillaria bulbosa growing in northern
Michigan covers only 0.2 km ² , but is
thought to be 10,000 years old. This
would make it the oldest known living
organism on the planet.

QUEENSLAND MUSEUM

BACTERIA

Text: Queensland Museum. Uncredited photography: Steve Parish

Bacteria are single-celled microorganisms and they are found
everywhere on Earth. They
grow in soil, hot acidic water,
radioactive waste, seawater and
even deep in the Earth’s crust.
While some are harmful, others are
vital for recycling nutrients in the
environment and for maintaining
the health of animals and plants.
Parasitic protozoans ( Trichodina spp. )
on the edge of a gill filament of a fish.

A parasite is an organism that lives in, or on, another plant or animal
and obtains its nourishment or some form of life support from the host
organism. Depending on the relationship with its host, a parasite may
cause little harm, but always benefits at the expense of the host.

1 mm
QUEENSLAND MUSEUM

DIFFERENT LIVES
The relationship between a parasite and its host can be very simple or extremely
complicated. Many internal parasites enter their host through their body tissues
( e.g. through cuts or insect bites ). At other times, the parasites are ingested through
certain foods. External parasites are often bloodsuckers that are present just long enough
to take a meal from the host. Some ectoparasites have elaborate ways of finding hosts,
using movement, temperature and chemical detection, while others simply wait in
“ambush” for a passing host. Parasites use tiny hooks, sucking mouthparts or claws to
attach themselves to their hosts.

Free-living adults
mate in water

Emerge and
mature in water

the
FACTS!
BACTERIA ARE TYPICALLY
a few micrometres long and are
shaped like curved rods, spheres
and spirals.

PARASITES THAT LIVE INSIDE
THE BODY OF A HOST are called
endoparasites. The intestinal worms
that can affect both humans and
animals are examples of endoparasites.
When a parasite lives on the outside
of a host’s body it is called an
ectoparasite. Fleas and some mites are
ectoparasites.There are even parasites
that feed on other parasites and these
are known as epiparasites.
Tapeworms of the genus Calliobothrium live
in the gut of vertebrates. The head ( scolex )
is armed with hooks that allow the worms
to grip the walls of the host’s intestine.

Disease Carriers

Parasites

BACTERIA CAN CAUSE
DISEASE in animals and humans,
but certain bacteria are used to
produce the antibiotics that fight
infection.
THE NAME “PARASITE” is derived
from the Greek word parasitos —
“to eat at another’s table”.
PARASITES AFFECT HUMANS as
well as our pets and animals.
THE DIFFERENCE BETWEEN a
predator and a parasite is a matter
of timing. Predators are only in
contact with prey long enough to
obtain a meal, while a parasite is
dependent on its host for much of
its life. Animals such as leeches
and mosquitoes, may be more
correctly called “micropredators”
rather than ectoparasites.
PARASITES ARE FOUND
EVERYWHERE and about 50%
of all animals are parasites. Every
healthy ecosystem is riddled with
parasites and they may well be
necessary for the proper functioning
of any given ecosystem.

Larva eaten by
insect; grows
and moults
Larva with
spiny proboscis

Eggs laid in
strings on weed

Above: Gordian worms are parasites of insects and spiders, but do not spend their whole life cycle
within the host. These worms are completely harmless to humans and other animals.
Right: Gordian worm emerging from a cricket.

THERE ARE TWO LICE that attack
humans. The Head Louse ( Pediculus
humanus capitus ) feeds on the scalp
and Phthirus pubis in the groin and
armpits. Infestations result in itchy,
irritated skin and the lice are spread
by close contact or shared clothing.

IN MOST CASES the disease pathogen
is transmitted when the insect’s mouthparts pierce the victim’s skin. In other
circumstances, the pathogen passes from
the insect carrier and gains entry to the host
through scratches or breaks in the skin, or
from contaminated food that is eaten.

BUBONIC PLAGUE caused
165 deaths in 1900 when it first
appeared in Australia. The disease
remained active for 10 years and
a total of 1212 cases of infection
were reported with 530 fatalities.
Most infections were recorded in
Sydney and others occurred in New
South Wales, Victoria, Queensland,
Western Australia and the Northern
Territory. Professional rat-catchers
(below) killed plague-carrying rats
during the 1902 Australian outbreak.

QUEENSLAND MUSEUM/JEFF WRIGHT

JOHN OXLEY LIBRARY/STATE LIBRARY OF QLD

Fortunately, no Australian sucking bugs
cause disease. Overseas, cone-nosed
and assassin bugs are known to
transmit harmful protozoans, particularly
Trypanosoma species, which cause a
range of serious illnesses.
Other insects, such as cockroaches ( order:
Blattodea ), may also carry pathogens that
affect human health, simply because they
live in dirty conditions.
Right: Australian native cockroaches are
common in gardens but none are domestic pests.

LOUSY LICE

DURING THE 1921 OUTBREAK
of bubonic plague, 35 cases were
reported in Sydney with ten deaths.
In Brisbane 59 people were struck
down with the disease and 28
eventually died.

BIOS/AUSCAPE

BUBONIC PLAGUE IS ALSO
KNOWN as “The Black Death”.
It is believed that the disease
caused the deaths of an estimated
25 million people during a pandemic
in the 14th century.

Text: Queensland Museum. Uncredited photography: Steve Parish

The Human Body Louse ( Pediculus
humanus ) is responsible for transmitting
epidemic typhus, one of the worst
diseases in history. Until the development
of a vaccine and antibiotics, epidemic
typhus claimed the lives of millions of
people around the world. It was once
widespread, but now largely occurs in
Central America, Asia and Africa. Although
body lice occur in Australia, epidemic
typhus does not. The bacterium that
causes the disease, Rickettsia prowazekii,
is transmitted when the louse bites.
Epidemic typhus is highly contagious
and spreads most easily in crowded
conditions, such as refugee camps, or
where hygiene is poor.
Left: A magnified (20x) picture of the Head
Louse (Pediculus humanus capitus).

the
FACTS!

PESKY FLEAS

CSIRO ENTOMOLOGY

Fleas, particularly Oriental Rat Fleas
( Xenopsylla cheopis ), have played a
central role in the spread of the ancient
scourge of humankind — bubonic plague.
The disease is caused by the bacterium
Yersinia pestis and spread by fleas to
rats, especially Black Rats ( Rattus rattus ),
and other rodents. Outbreaks of bubonic
plague occurred in Australia between
1900–1910 and again in 1921 due to
diseased rats escaping from ships.

AMERICAN COCKROACHES
(below) are one of four introduced
pest cockroaches that infest homes
and buildings. They generally live in
moist areas and are usually found
in sewers, crawl spaces, cracks,
crevices and foundations. American
Cockroaches feed on a wide variety
of foodstuffs as well as other plant
and animal material.

The insects can bite viciously, causing
pain and discomfort. With the
exception of mosquitoes, Australian
biting flies are not known to transmit
disease. Reactions to fly bites are
usually confined to irritation and
sometimes severe allergic responses.

THE GERMAN COCKROACH is
the smallest of the pest species,
with adults growing to 1.5 cm in
length. It is the most troublesome
pest cockroach and the most
difficult to eradicate. One female
German Cockroach can produce up
to 20,000 young annually.

Bushflies ( Musca vetustissima ) breed in
cattle dung. The adults are a summertime
nuisance when they cluster on humans
in large numbers and crawl in the eyes,
mouth and nose.

The so-called Australian Cockroach is not native to
Australia. They originated in Asia and have become
totally adapted to domestic life. These cockroaches
can contaminate food and are potential sources of
disease in homes and restaurants.

THE HOUSE FLY ( Musca
domestica, below ) is a common
and familiar pest around dwellings,
stables, chicken sheds and rubbish
tips. It is found worldwide.

The German Cockroach ( Blatella
germanica ), the American Cockroach
( Periplaneta americana ), the Smoky-brown
Cockroach ( P. fuliginosa ) and the
Australian Cockroach ( P. australasiae ) are
common household pests throughout
Australia. All species are introduced.
These cockroaches live in drains, sewers,
rubbish tips, grease traps, ceilings and
damp cellars as well as under floors. They
enter houses and contaminate food with
excrement, regurgitated salivary fluid and
potentially harmful bacteria.

Glossary
ADAPT To change physical features
over time in order to fit into a particular
environment.
AMBUSH A sudden and surprise
attack.
ANTIVENOM A serum used to treat
a person who has been attacked by a
venomous animal.
ARACHNID Eight-legged invertebrate
(such as spiders, scorpions and their
relatives).
BACTERIA Single-celled microorganisms found in every habitat on
Earth.
BARBELS Slender, fleshy feelers
around the mouths of some types of
fish (e.g. catfish).
CAMOUFLAGE Colouring that helps
an animal blend in with its backgound.
CARAPACE A hard shell that covers
the top and sides of an animal’s body.
CARNIVORE An animal that eats
meat and other animals.
CEPHALOPODS A class of molluscs
that includes squids, octopuses and
their relatives.
CHELIPEDS Claws/pincers.
CIGUATOXIN A marine poison found
in dangerous levels in some large reef
fish.
CNIDARIAN Any marine creature of
the phylum Cnidaria (corals, hydroids,
sea anemones, sea jellies and their
relatives).
COLUBRID Any snake that belongs
to the Colubridae family. Unlike elapids,
Colubrids either lack fangs or have
them at the rear of the mouth.
CRUSTACEAN Crabs, crayfish,
prawns and their relatives.
DINOFLAGELLATE Microscopic,
single-celled aquatic organisms.

ECHINODERM Any slow-moving
marine creature that belongs to the
phylum Echinodermata (sea stars, sea
urchins and their relatives).
ELAPID A snake with hollow fangs
positioned at the front of the upper jaw
and used for injecting venom.
EXTINCT When an animal, plant, or
other living organism ceases to exist.
FERAL A domestic animal (e.g. cat)
that has become wild.
GENUS A type, or kind, of animal
or plant. The first Latin name of an
animal’s or plant’s scientific name is the
genus. Different species can share the
same genus.

POLYP Attaching invertebrates that
have a single body cavity. A polyp is
one of two basic cnidarian body types.
PREDATOR An animal that hunts and
eats other animals.
PROBOSCIS A long, tubular snout or
feeding organ.
PROTOZOA Single-celled organisms
that can cause serious diseases (such
as malaria).
RADULA The rasp-like tongue of most
molluscs.
ROSTRUM Part of animal’s body that
extends out (e.g. a beak).

HERBIVORE An animal that eats
plants.

SPECIES A group of animals that
share the same physical features and
can breed together to produce fertile
young.

HOST The organism that supports a
parasite.

SPICULE A small, slender, sharppointed body part.

INVERTEBRATE An animal that does
not have a backbone.

SYMBIOTIC A mutually beneficial
relationship between two different
species.

LARVA (Plural: Larvae) The young form
of an animal after it hatches and before
it changes into an adult.
MEDUSA (Plural: Medusae) A freeswimming cnidarian (such as a sea
jelly). One of two main cnidarian body
types.
MOLLUSC An invertebrate animal with
a soft body and (usually) a shell.
NEMATOCYSTS Stinging cells.
PARASITE An animal or plant that
lives on or in another species (the host)
and takes nourishment from them.
PATHOGEN Disease-causing agent.

TOXIN A poisonous substance
produced by living creatures.
VENOM Toxins made by animals that
can be injected into prey (via stings,
spines, sprays and fangs).
VIRUS A sub-microscopic “agent” that
replicates by invading the cells of living
organisms.
VULNERABLE A species that has
declined and could be at risk of
extinction.
ZOOXANTHELLAE Tiny algae that
give coral its colour.

PEDICELLARIAE Tiny pincerlike structures commonly found on
echinoderms.
POLLUTANTS Domestic, agricultural
and industrial chemicals that pass into
the environment.